=============================== [ INFO: suspicious RCU usage. ] 4.9.77-ge12a9c4 #18 Not tainted ------------------------------- kernel/rcu/tree_plugin.h:672 Illegal synchronize_rcu() in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 3 locks held by syz-executor5/3398: #0: (tasklist_lock){.+.+..}, at: [] do_wait+0x394/0x950 kernel/exit.c:1558 #1: (rcu_read_lock){......}, at: [] INIT_LIST_HEAD include/linux/list.h:28 [inline] #1: (rcu_read_lock){......}, at: [] avc_compute_av+0xad/0x640 security/selinux/avc.c:975 #2: (rcu_callback){......}, at: [] __rcu_reclaim kernel/rcu/rcu.h:108 [inline] #2: (rcu_callback){......}, at: [] rcu_do_batch kernel/rcu/tree.c:2789 [inline] #2: (rcu_callback){......}, at: [] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] #2: (rcu_callback){......}, at: [] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] #2: (rcu_callback){......}, at: [] rcu_process_callbacks+0x977/0x1300 kernel/rcu/tree.c:3037 stack backtrace: CPU: 0 PID: 3398 Comm: syz-executor5 Not tainted 4.9.77-ge12a9c4 #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801db207d50 ffffffff81d941c9 ffff8801b5154800 0000000000000000 0000000000000002 ffffffff83a6d3c0 ffff8801c9449558 ffff8801db207d80 ffffffff812382a9 ffff8801c9449400 ffff8801d4a12a48 ffff8801d4a12248 Call Trace: [ 61.793817] [] __dump_stack lib/dump_stack.c:15 [inline] [ 61.793817] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] lockdep_rcu_suspicious+0x139/0x180 kernel/locking/lockdep.c:4455 [] synchronize_rcu+0x68/0x90 kernel/rcu/tree_plugin.h:669 [] __l2tp_session_unhash+0x3d5/0x550 net/l2tp/l2tp_core.c:1792 [] l2tp_tunnel_closeall+0x1e7/0x3a0 net/l2tp/l2tp_core.c:1364 [] l2tp_tunnel_destruct+0x30e/0x5a0 net/l2tp/l2tp_core.c:1324 [] __sk_destruct+0x53/0x570 net/core/sock.c:1428 [] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [] rcu_do_batch kernel/rcu/tree.c:2789 [inline] [] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] [] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] [] rcu_process_callbacks+0x898/0x1300 kernel/rcu/tree.c:3037 [] __do_softirq+0x206/0x951 kernel/softirq.c:284 [] invoke_softirq kernel/softirq.c:364 [inline] [] irq_exit+0x165/0x190 kernel/softirq.c:405 [] exiting_irq arch/x86/include/asm/apic.h:659 [inline] [] smp_apic_timer_interrupt+0x7b/0xa0 arch/x86/kernel/apic/apic.c:960 [] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:741 [ 61.912540] [] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline] [ 61.912540] [] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline] [ 61.912540] [] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191 [] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline] [] avc_reclaim_node security/selinux/avc.c:543 [inline] [] avc_alloc_node+0x27a/0x3e0 security/selinux/avc.c:561 [] avc_insert security/selinux/avc.c:672 [inline] [] avc_compute_av+0x182/0x640 security/selinux/avc.c:978 [] avc_has_perm_noaudit security/selinux/avc.c:1114 [inline] [] avc_has_perm+0x378/0x4f0 security/selinux/avc.c:1148 [] task_has_perm+0x200/0x340 security/selinux/hooks.c:1631 [] selinux_task_wait+0x23/0x30 security/selinux/hooks.c:3966 [] security_task_wait+0x6d/0xa0 security/security.c:1032 [] wait_consider_task+0x221/0x36a0 kernel/exit.c:1377 [] do_wait_thread kernel/exit.c:1490 [inline] [] do_wait+0x423/0x950 kernel/exit.c:1561 [] SYSC_wait4 kernel/exit.c:1689 [inline] [] SyS_wait4+0x10e/0x1d0 kernel/exit.c:1658 [] entry_SYSCALL_64_fastpath+0x29/0xe8 ODEBUG: object is not on stack, but annotated ------------[ cut here ]------------ WARNING: CPU: 0 PID: 3398 at lib/debugobjects.c:300 debug_object_is_on_stack lib/debugobjects.c:300 [inline] WARNING: CPU: 0 PID: 3398 at lib/debugobjects.c:300 __debug_object_init+0x526/0xc40 lib/debugobjects.c:326